presents a valid unexpired passport or other suitable travel document, or document of identity and nationality, if such document is required under the regulations issued by the Attorney General. With respect to immigrants to be admitted under quotas of quota areas prior to June 30, 1968, no immigrant visa shall be deemed valid unless the immigrant is properly chargeable to the quota area under the quota of which the visa is issued.

Notwithstanding the provisions of
section
212(a)(7)(A)
of this Act
[8 U.S.C 1182(a)(7)(A)]
in such cases or in such classes of cases and under such conditions as may be by regulations prescribed, returning resident immigrants, defined in
section
101(a)(27)(A)
of this Act
[8 U.S.C 1101(a)(27)(A)]
, who are otherwise admissible may be readmitted to the United States by the Attorney General in his discretion without being required to obtain a passport, immigrant visa, reentry permit or other documentation.